1. Field of the Invention
This invention relates to a steering system in which a plurality of switches carrying marks for various controls are mounted on a steering wheel.
2. Description of Related Art
There have been proposed in recent years such steering systems of motor vehicles that a plurality of switches indicating marks for various controls are mounted on a steering wheel, so that operators of the motor vehicles can readily operate the switches.
For instance, the steering system disclosed in Japanese Pat. No. Hei 6-270816 incorporates a switch unit having many kinds of switch knobs in the lower part of the steering wheel surface, and adapted to improve operation performance. The switch unit is comprised of a plurality of pushbutton switches including an automatic speed control switch, an audio switch, an air-conditioner switch having various kinds of functions; a plurality of switch knobs for on-off operation of these pushbutton switches; and a casing for holding these switches and switch knobs. The upper part of each of the switch knobs projects out of a window hole provided in the upper surface of the casing.
The switch unit thus constituted is fixedly attached in a specific position of the steering wheel. When the operator presses a switch knob to operate the steering wheel, a pushbutton switch is depressed to ON position correspondingly to the pressing of the switch knob, giving off an ON signal. According to the ON signal from the switch, specific control operation is performed correspondingly to the switch knob.
In the case of the aforesaid prior art switch system, details of control are unequivocally determined according to a switch unit incorporated in the steering wheel. It is impossible to change the array of switches having specific functions to his need and to provide the switches with different functions in place of existing functions. The prior art switches, therefore, require an improvement in ease of operation.
This invention, therefore, has an object to provide a steering system in which a plurality of switch knobs indicating various functions and a plurality of self-function detecting switches which output an identifying signal in accordance with the function of each switch knob are mounted on the steering wheel. According to this constitution, various kinds of identifying signals are outputted in accordance with the combination of the switch knobs and the self-function detecting switches. Therefore, switches having specific functions may be changed in arrangement to the operator""s need; and also existing functions of switches may be replaced with other functions.
In the steering system of this invention, a plurality of switch knobs indicating various different kinds of functions and a plurality of self-function detecting switches which output an identifying signal according to the function of each switch knob are mounted on the steering wheel.
Since varied identifying signals are outputted by the combination of the switch knob and the self-function detecting switch according to this configuration, switches having specific functions maybe changed to the operator""s need, and the existing functions of switches may be replaced with other functions, thereby improving convenience of operation.
The self-function detecting switch may be any type of detecting switch so long as it outputs various kinds of identifying signals in combination with a switch knob corresponding thereto. It is, however, desirable that the self-function detecting switch be provided with a plurality of driving pins which are capable of mutually independently changing over contact points, and also that the switch knob be provided with a driving section which is capable of simultaneously pressing one driving pin or a plurality of driving pins provided on the self-function detecting switch corresponding thereto, so that different identifying signal from each self-function detecting switch can be outputted in accordance with the shape of the driving sections.
According to the above-described constitution, the switching function can be altered simply by replacing the switch knob, thereby enabling to reduce the manufacturing cost of the self-function detecting switch and also allowing the operator to easily change the switching function. At this time, there may be adopted one set of self-function detecting switches including a plurality of single pin-type push switches having one driving pin; besides, multiple push switches having a plurality of driving pins projecting out from a common cabinet may be used as one set of self-function detecting switches.
When the steering wheel is fitted with an openable holding cover, which is locked in a closed state to prevent the switch knob from falling, it is possible to prevent the switch knob from flying out and hitting against the operator in the event of a collision of the motor vehicle. Also, the switch knob can easily be replaced by unlocking and opening the holding cover.
Furthermore, when the detecting switch for detecting the opening-closing operation of the holding cover and a warning means which is operated by an output signal generated by the detecting switch are provided, the operator will be warned by the warning means such as a buzzer and a lamp, of the state that the holing cover is left unclosed.
Other objects, features and advantages of this invention will be apparent from the following detailed description taken in connection with the accompanying drawings.